The use of modular plugs and jacks for data transmission is known. Basically, in order to establish electrical communication and a data path between a first and second device, the first device may send information in the form of electrical signals out into a cable that terminates in a plug. The second device may include a jack. The plug and jack are designed so as to be easily mechanically mate-able in a male-female configuration. Once the plug and jack are mated, electrical members in the plug and connector engage and are electrically mated so that electrical information signals may travel from the first device to the second device.
This plug and jack design is limited by the physical configuration of the modular plug and jack. As data transmission speeds have increased, electrical performance relating to the transfer of electrical signals from plug to connector, has been affected. Each plug and jack frequently includes multiple pairs of contacts used to communicate information. Cross talk between these pairs (where electrical signals in one pair affect electrical signals in another pair) and interference from sources external to the plug-jack configuration, become more of a factor at higher speeds. In order to carry the higher speed data without signal degradation, the plug and jack design changed to include compensation circuitry such as that used to balanced impedance in transmission lines.
Standards organizations such as the Telecommunication Industry Association and the International Organization for Standardization publish standards regarding performance specifications and equipment configurations for plugs and jacks. Different levels or “categories” have been defined for use in twisted-pair cabling such as where a single insulated sheath includes two twisted wires. For example, “Category 6” plugs and jacks should be able to handle data communications with a frequency up to 250 MHz. Category 6 plugs typically have eight contacts aligned in a row on one side of the plug. More recent requirements, e.g. Category 7, require plugs and jacks which can communicate at speeds as high as 600 MHz.
The balanced line compensation approach discussed above proved acceptable for performance levels up to Category 6 i.e., 250 MHz. In order to meet the electrical requirements of the transmission speeds specified in Category 7, the cross talk and interference generally could not be canceled out using only balanced line compensation and so the contacts were moved to opposite sides of the plug and jack. As the industry is evolving from Category 6 to Category 7 usage, it is desirable to provide a jack that can receive and communicate with plugs using either standard. Providing such a connector is difficult because while eight (8) coplanar contacts had been used in Category 6 applications, in Category 7, the eight contacts are spaced in two different planes on opposite sides of the jack so as to minimize crosstalk between signal pairs.
An example of a prior art jack which may be used for both Category 6 and Category 7 communications is shown in U.S. Pat. No. 6,739,892 and is reproduced in part, in FIG. 1. Referring to FIG. 1, a prior art connector 50 consists of a shield 52, a dielectric housing 54, a switch insert 56 and a circuit board sub-assembly 58. When assembled, sub-assembly 58 is inserted into switch insert 56, switch insert 56 is inserted into housing 54, and housing 54 is inserted into shield 52. When a Category 6 plug is inserted into jack 50, terminals on sub-assembly 58 engage corresponding terminals of the plug for data communication. If a Category 7 plug is inserted into jack 50, a protrusion on the plug engages a switch 60 on switch insert 56. Switch 60 causes some of the terminals in connector 50 to be lifted away from electrical connection and moved into contact with a grounding member (not shown).
There are problems with the prior art connector shown in FIG. 1. Requiring a switch to disengage or ground some of the terminals increases the complexity of the device. Moreover, there is the possibility of an open circuit especially if there is a failure in the switch.